Summary

Organisms of various kingdoms have been reported to deposit a variety of different minerals through biomineralisation 53. Key features of biomineralisation are the precise hierarchical control over structural growth of biominerals, species-specificity of the biomineral morphology, and ambient conditions (temperature and pH) for formation. The deposition of amorphous silica to form ornate frustules through biosilicification in diatoms is one example. In addition, biomineralisation is facilitated and controlled by various characteristic proteins in each biological system. The entrapment of the catalysing / templating / scaffolding biomacromolecules enables them to be recovered by selective dissolution of the biomineral. Study of these proteins, thus, is of interest in understanding biomineralisation. The proteins extracted from the diatom Cylindrothecafusiformis (silaffins) and the sponge Tethya aurantia (silicateins) have been shown to precipitate silica from silica precursors in vitro. Furthermore, this understanding helps us to design biomimetic materials, new processes, and applications based on the aforesaid minerals in a bioinspired synthetic manner in vitro. The identification of synthetic macromolecules that can act as catalysts/ templates/ scaffolds for silica formation gives exciting possibilities for bioinspired silica synthesis.